In the vast, logical, and obsessively-codified machine of UK immigration law, there is a "rule" for everything. You are a "Spouse" (Appendix FM). You are a "Skilled Worker" (Appendix Skilled Worker). You are a "Student" (Appendix Student). Your life, your skills, and your relationships must be forced into one https://www.immigrationsolicitors4me.co.uk/Discretionary-leave-outside-the-immigration-rules